Cloth feed mechanism for sewing machines



Feb. 24, 1959 L. BONO CLOTH FEED MECHANISM FOR SEWING MACHINES F'iled Aug. 4. 1954 IN VENTOR. L ale-l B a N0 BY fli mzj WWW CLOTH FEED MECHANISM FOR SEWING MACHINES Luigi Bono, Pavia, Italy, assignor to Vittorio N ecchi Societ per Azioni, Pavia, Italy Application August 4, 1954, Serial No. 447,819

6 'Claims. or. 112-215 The present invention relates to a cloth feeding mechanism for sewing machines.

An object of the invention is to provide a new and improved simplified movement .for the'feed dog wherein such feed dog is reciprocated in a horizontal plane and in a vertical plane.

A further object of the invention is to provide a device which can be advantageously used on machines which have a limited space available such as sewing machines for sewing sleeves, stockings, etc.

With the above and other objects in view which will become apparent from the detailed description below, a preferred embodiment of the invention is shown in the drawings in which: i

Figure 1 is a cross-sectional view taken upon section line I-I of Figure 2.

Figure 2 is a plan view of the feeding mechanism, and

Figure 3 is a diagrammatical view illustrating the particular movements involved.

1n the various views similar reference characters indicate like parts.

The feeding mechanism comprises a plate 1 fixed to a shaft 2 which is oscillated about its axis by any means connected to the main shaft of the sewing machine.

The plate 1 is hinged to a frame, comprising the rods 4 and 4' by means of the pin 3 and the rods 4 and 4' are hinged to a plate 5 by means of the pin 6. The feed dog 7 is secured by the two screws 8 to the plate 5. See Figure 2.

A shaft 9 which is connected in any desired manner to the main shaft of the sewing machine oscillates about its axis and carries at one of its ends a cam 10 which cooperates with a disc 11 fixed to the plate 5 by means of the screw 12.

A lever 13 which is a bell crank lever having two arms is fulcrumed upon a pin 14 which is fixed to the rods 4 and 4'. The end 13' of the lever 13 bears against the roll 15 and the other end 13" of the lever 13 contacts the lower surface of the feed dog 7.

The roll 15 is secured to the base 16 of the machine by means of a support 17. A spring 18 has one end secured to the plate 5 while the other end is secured to the plate 1. The spring 18 maintains the ends 13 and 13" of the lever 13 constantly in contact with both the roll 15 and the lower surface of the feed dog 7.

The device operates as follows. The reciprocating horizontal movements of the feed dog are obtained by the oscillation of the plate 1 which by means of the rods 4 and 4' causes the disc 11 and the feed dog 7 connected thereto to slide forwardly and backwardly.

The cam 9 oscillating about its axis causes the disc 11 and the feed dog 7 connected therewith to rise and fall. During these movements the feed dog always remains horizontal due to the action of the lever 13.

The oscillations of the rods 4 and 4' about the pin 3 which are caused by the oscillations of the cam 10 cause a displacement of the lever 13 which will keep the end 13" maintaining the feed dog 7 always at the same nited States Patent 0 2,874,662 vPatent ed Feb. 24, 1959 level with respect to the pin 6 and the end 13' which always is in contact with the roll 15.

. The above result is obtained in view of the particular articulated system used as illustrated diagrammatically in Figure 3. The side between the pins 3 and 14 is approximately equal to the distance between the pin 14 and the point of contact between the lever 13 and the roll 15.

Furthermore the portion of the rod 4 between the pins 14 and 6 is equal to the distance between the pin 14 and the end 13" of the lever 13.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in the drawings being merely a preferred embodiment thereof.

What I claim is:

l. A feed mechanism for a sewing machine comprising a plate, a feed dog fixed to said plate, a frame having said plate pivotally connected at one end thereof, means for horizontally reciprocating said frame pivotally connected to the other end of said frame, a bell crank lever fulcrumed upon said frame, one arm of said bell crank lever having a length approximately equal to the distance between the fulcrum of said bell crank lever and the point of pivotal connection of said frame to said means for horizontally reciprocating said frame, a roller fixed to the machine with which the end of said arm slidably, cooperates, the other arm of said bell crank lever having a length approximately equal to the distance between the fulcrum of said bell crank lever and the point where said plate is pivotally connected to said frame, means for vertically reciprocating said plate and said feed dog carried thereby and spring means interconnecting said means for horizontally reciprocating said frame and said plate.

2. A feed mechanism for a sewing machine comprising a plate, a feed dog fixed to said plate, a frame, said plate being pivotally connected to said frame, means for horizontally reciprocating said frame, a bell crank lever fulcrumed upon said frame below said plate, one arm of said lever having a length approximately equal to the distance between the fulcrum of said lever and the point of pivotal connection of said frame to- 'said means for horizontally reciprocating said frame,-means fixed to the machine with which the end of said arm slidably coto said frame, means for vertically reciprocating said plate and feed dog carried thereby and means maintaining contact between said plate and the arm of the lever cooperating therewith, said bell crank lever being fulcrumed upon said frame intermediate said means for horizontally reciprocating said frame and where said plate is pivotally connected to said frame.

3. A feed mechanism for a sewing machine comprising a plate, a feed dog fixed to said plate, a frame, said plate being pivotally connected to said frame, means for horizontally reciprocating said frame, a bell crank lever fulcrumed upon said frame below said plate, a roller fixed upon the machine with which one arm of said bell crank lever slidably cooperates, the other arm of said bell crank lever cooperating with said feed dog, means for vertically reciprocating said plate and the feed dog carried thereby and means maintaining a contact between said plate and the arm of the lever cooperating therewith, said bell crank lever being fulcrumed upon said frame intermediate said means for horizontally reciprocating said frame and where said plate is pivotally connected to said frame.

4. A feed mechanism for a sewing machine comprising aplate, a feed dog fixed to said plate, a frame having said plate pivotally connected at one end thereof, means for horizontally reciprocating said frame pivotally connected to the other end of said frame, a bell crank lever fulcrumed upon said frame below said plate, one arm of said lever having a length approximately equal to the distance between the fulcrum of said lever and the point of pivotal connection of said frame to said means for horizontally reciprocating said frame, a roller fixed to the machine with which the end of said arm slidably cooperates, the other arm of said lever being in contact with said plate and having a'length approximately equal to the distance between the fulcrum of said lever and the point where said plate is pivotally connected to said frame, means for vertically reciprocating said plate and said feed dog carried thereby and means maintaining contact between said plate and the arm of the lever cooperating therewith, said bell crank lever being fulcrumed upon said frame intermediate said means for horizontally reciprocating said frame and where saidplate is pivotally connected to said frame.

5. A feed mechanism for a sewing machine comprising aframe having two ends, one of said ends being supported for free reciprocating movement in the plane of said frame, means for reciprocating said end, a support for the other end of said frame allowing free movement thereof in the plane of the frame, means for reciprocating said support transversely to the plane of said support transversely to the plane of said frame, a plate hinged on said frame, a feed dog supported by said plate, a two armed bell crank lever hinged on said frame below 'said plate, means fixed on said machine with which one arm of said two armed-lever slidably cooperates, the other arm of said two armed lever being slidably connected to said plate, said bell crank lever being hinged upon said frame intermediate said means for horizontally reciprocating 4 said frame and where said plate is pivotally connected to said frame.

6. A feed mechanism for a sewing machine comprising a frame having two ends, one of said ends being supported for free reciprocating movement in the plane of said frame, means for reciprocating said end, a support for the other end of said frame allowing free movement thereof in the plane of the frame, means for reciprocating said support transversely to the plane of said support transversely to the plane of said frame, a plate hinged on said frame, a feed dog supported by said plate, a two armed bell crank lever hinged on said frame below said plate, means fixed on said machine with which one arm of said two armed lever slidably cooperates, the other arm of said two armed lever being slidably connected to said plate, one arm of said two armed lever having a length approximately equal to the distance between the point where said lever is hinged on said frame and the point where said plate is hinged to said means for reciprocating said frame in the plane of said frame and the other arm of said lever having a length approximately equal to the distance between the point where said lever is hinged to said frame and the point where said plate is pivotally connected to said frame, said bell crank lever being hinged upon said frame intermediate said means for horizontally reciprocating said frame and where said plate is pivotally connected to said frame.

References Cited in the file of this patent UNITED STATES PATENTS 509,744 Leconte Nov. 28, 1893 1,054,715 Richards Mar. 4, 1913 1,581,524 Wardwell Apr. 20, 1926 2,496,817 Schulthess Feb. 7, 1950 FOREIGN PATENTS 685,636 Germany Nov. 30, 1939 

